Highly shaped aluminum products, including, among others, aluminum cans and/or aluminum bottles for beverages, are manufactured from blanks that are cut from aluminum sheet. Each blank, which is generally circular in shape, is then formed into a cup with a circular base and a vertical wall. During the transition from a relatively two-dimensional circular sheet to a three-dimensional cup, the metal of the blank can become distorted. The resulting waviness around the rim of the cup may be referred to as earing, and the varying thickness of the material around the edge may be referred to as wrinkling. This distortion may become more pronounced as the cup moves through further production processes, such as conventional high speed drawing and wall ironing (DWI), to become a preform.
Earing, wrinkling, and other distortions of the aluminum cup and/or preform, particularly for production of aluminum bottles that require forming a neck, may cause the final highly shaped products to require extra processing steps, trimming of the distorted edges of the cup and/or preform, and may lead to a tendency to fracture the preform. Inconsistent properties of the metal around the circumference of the opening of the cup, preform, and/or neck of a bottle cause increased waste and a reduction in production efficiency by requiring extra trimming and processing steps.